Aer Lingus has been the best performing unit within the International Consolidated Airlines Group (IAG) so far this year according to traffic figures published by its parent company.

IAG measures its performance using revenue passenger kilometres, a metric combining revenue with distance flown by passengers. By that measure Aer Lingus traffic is ahead 13.7% over the first five months of the year. 

That's well ahead of the other brands - BA, Iberia and Vueling - within IAG. The next best performer was Spanish airline Vueling where traffic rose 8.4%.

IAG notes that BA's performance in May was impacted by a serious technology-related incident in the last weekend of the month when a power failure knocked out its servers and led to hundreds of cancellations.